Eccrine porocarcinoma of the head and neck: Meta-analysis of 120 cases

Porocarcinoma: Clinical and Histological Features, Immunohistochemistry and Outcomes: A Systematic Review

Porocarcinoma (PC) is a rare adnexal tumor, mainly found in the elderly. The tumor arises from the acrosyringium of eccrine sweat glands. The risk of lymph node and distant metastasis is high. Differential diagnosis with squamous cell carcinoma is difficult, although NUT expression and YAP1 fusion products can be very useful for diagnosis. Currently, wide local excision is the main surgical treatment, although Mohs micrographic surgery is promising. To date, there is no consensus regarding the role of sentinel lymph node biopsy and consequential lymph node dissection. No guidelines exist for radiotherapy, which is mostly performed based on tumor characteristics and excision margins. Only a few studies report systemic treatment for advanced PC, although therapy with pembrolizumab and EGFR inhibitors show promise. In this review, we discuss epidemiology, clinical features, histopathological features, immunohistochemistry and fusion products, surgical management and survival outcomes according to stage, surgical management, radiotherapy and systemic therapy.

Navigating Head and Neck Porocarcinoma: Systematic Review with Special Emphasis on Surgical Safety Margins

Eccrine porocarcinoma, sharing many features with other skin tumours, is diagnostically challenging. A conventional biopsy might be misleading and surgical excision becomes a primary diagnostic tool and a treatment method. However, the data on surgical safety margins are not consistent. We present a systematic review analysing the surgical margins of porocarcinoma in the head and neck area, which was conducted across the PubMed, Cochrane, and Web of Science databases including studies published from inception to November of 2023. In this systematic review, the PRISMA-ScR checklist was used, and a Cohen's Kappa coefficient of 0.92 was applied, indicating very good agreement between reviewers. Out of 529 identified articles, 18 studies yielding 20 cases in total were selected for a thorough analysis. Nine (45%) cases were observed in the facial regions, eight (40%) on the scalp, and three (5%) on the neck. The primary treatment of choice was wide local excision with safety margins ranging from 3 to 22 mm (mean: 10.1). It demonstrated that surgical margins do not differ by age or anatomic regions, with the main point of reference being the tumour size. As observed, the bigger the tumour, the wider the safety margins were. However, the limited disclosure of surgical safety margins in analysed case reports impeded our ability to define the minimum safety margins. Further investigation and a consensus on recommended safety margins are required.

Eccrine Poroma: Pathogenesis, New Diagnostic Tools and Association with Porocarcinoma-A Review

Eccrine poroma (EP) is a relatively rare benign adnexal neoplasm that usually affects elderly patients. Its pathogenesis is still under investigation, but recent gene studies have revealed gene fusions as key incidences resulting in oncogenetic pathways. It often presents as a solitary, firm papule, mostly asymptomatic, located on the soles or palms. Due to its clinical and dermoscopic variability, it is characterized as the great imitator. We performed a literature review, aiming to summarize current data on the pathogenetic mechanisms, new dermoscopic features, and novel diagnostic tools that may aid in early diagnosis and proper management of this rare adnexal tumor. Furthermore, we reviewed the possible pathogenetic associations between EP and its malignant counterpart, namely eccrine porocarcinoma. This systematic approach may aid in understanding the pathogenetic mechanisms and how to use novel histopathologic markers and imaging methods to overcome the diagnostic dilemma of this rare tumor.

When to sweat: A history of chemotherapy in malignant sweat gland tumors. A unique case report and literature review

Sarcomatoid sweat gland carcinomas are rare among cutaneous cancers, with less than 20 cases described. A 54-year-old woman with sarcomatoid sweat gland carcinoma of the right upper extremity suffered extensive recurrence at 15 months, unresponsive to chemotherapy. There is no standard treatment or chemotherapy regimens for metastatic sweat gland carcinoma.

Radiotherapy of skin adnexal carcinoma

Skin adnexal carcinomas are rare skin cancer, developing from pilosebaceous, eccrine and apocrine unit. Treatment of localised tumours usually includes surgery and radiotherapy. Indications and modalities of radiotherapy depend on the pathological subtype with a lack of consensus for some histologies. This review summarises the place of radiotherapy in terms of indication, dose and fractionation, volumes to irradiate and discuss ongoing studies.

Eccrine Porocarcinoma: A Review of the Literature

Eccrine porocarcinoma (EPC) constitutes a rare malignant adnexal tumor, which accounts for about 0.005-0.01% of all cutaneous malignancies. It may develop de novo or arise from an eccrine poroma, after a latency period of years or even decades. Accumulating data suggest that specific oncogenic drivers and signaling pathways may be implicated in its tumorigenesis, while recent data have demonstrated a high overall mutation rate attributed to UV exposure. Diagnosis may be challenging and should rely on the combination of clinical, dermoscopical, histopathological and immunohistochemical findings. The literature is controversial regarding tumor behavior and prognosis and, therefore, there is no consensus on its surgical management, utility of lymph-node biopsy and further adjuvant or systemic treatment. However, recent advances in tumorigenesis of EPC may aid in the development of novel treatment strategies, which could improve survival of advanced or metastatic disease, such as immunotherapy. This review presents an update of the epidemiology, pathogenesis and clinical presentation of EPC and summarizes current data on diagnostic evaluation and management of this rare cutaneous malignancy.

Challenges in the diagnosis and treatment of the malignant adnexal neoplasms of the head and neck

PURPOSE OF REVIEW

The current review is to present the current knowledge regarding epidemiology, diagnostics, and management of malignant adnexal neoplasms (MANs).

RECENT FINDINGS

Immunotherapy and gene-related therapies are still being developed as the methods of salvage treatment in advanced and disseminated cases: CACNA1S, ATP2A1, RYR1, and MYLK3, as well as p53 or the JAK/STAT pathways, may be therapeutic targets; the efficiency of talimogene laherparepvec and nivolumab is assessed.

SUMMARY

MANs are rare tumors, but due to the aging of population their incidence is increasing. Their clinical presentation is unspecific, which makes the diagnosis challenging. Histopathological assessment is difficult even for experienced pathologists. Mohs micrographic surgery or wide local excision are recommended to treat primary lesions. Adjuvant radiotherapy may be beneficial in case of insufficient or positive surgical margins, in nodal metastases, in selected types of MANs like sebaceous, trichilemmal, and pilomatrix carcinomas, and as the induction treatment in large tumors located in medically fragile or cosmetically important regions. The role of chemotherapy is not well defined; however, it is recommended in distant metastases. Immunotherapy can improve the prognosis in advanced stage of the disease.

Primary Eccrine Porocarcinoma of the Breast: A Case Report and Review of Literature

Eccrine porocarcinoma (EPC) is a rare cutaneous neoplasm, with less than 500 reported cases worldwide since it was first described in 1963. EPC tends to affect the elderly and most commonly affects the head and neck. The mainstay of EPC treatment is surgery, with lymphadenectomy in the case of nodal involvement or presence of unfavourable characteristics. No evidence exists to guide the use of adjuvant chemotherapy or radiation. EPC is prone to misdiagnosis given its multiple clinical and histopathological mimics, especially in uncommon sites of presentation such as the breast. Herein, we report the case of a 59-year-old woman who presented with a left breast skin lump. The biopsied specimen revealed an infiltrative carcinoma involving the dermis and epidermis with positive IHC staining for P63 and CK5/6 and negative staining for ER, PR, and HER2. The tumour was resected and diagnosed as EPC with atypical features as overlapping characteristics of squamous cell carcinoma (SCC) were detected on histopathological analysis. In our case, a simple mastectomy with broad margins and axillary lymph node dissection with adjuvant radiotherapy to a dose of 60 Gy failed to achieve loco-regional control with nodal recurrence occurring 4 months postsurgery-a testament to the aggressive course of this rare malignancy.

Head and Neck Porocarcinoma: SEER Analysis of Epidemiology and Survival

Porocarcinoma is a rare malignant adnexal tumor. Little is known about the location of the disease in the head and neck. Our aim is to offer the largest analysis of demographic, pathological, and treatment patterns of head and neck porocarcinoma in comparison with other locations of the neoplasm from an epidemiologically representative cohort. Method: The Surveillance, Epidemiology, and End Results program of the National Cancer Institute was searched for all cases of porocarcinomas diagnosed between 2000 and 2018. This database is considered representative of the US population. Demographic, pathological, and treatment variables were compared between the head and neck and other regions. Overall and disease-specific survival was calculated and compared between groups. Results: 563 porocarcinomas were identified, with 172 in the head and neck. The mean age was 66.4 years. Males were more affected in the head and neck. Regional and distant invasion rates were low (2.9 and 2.3%, respectively). Local excision and Mohs surgery were the most frequent therapies. Five-year overall survival was 74.8%. Five-year disease-specific survival was 97%. Conclusions: Head and neck porocarcinoma affects more males than females. Regional or distant metastatic rates are low and overestimated in previous literature. Disease-specific mortality is low. Surgery remains the mainstay of treatment.

Porocarcinoma: an epidemiological, clinical, and dermoscopic 20-year study

BACKGROUND

Porocarcinoma (PC) is a rare cutaneous adnexal tumor with a variable metastatic potential. Given the paucity of data, guidelines and specific recommendations for PC are not yet well-established. In this study, we evaluate the disease-specific characteristics and outcome of this rare and often underestimated tumor.

MATERIALS AND METHOD

A retrospective study of the epidemiological, clinical, and dermoscopic characteristics among cases of histopathologically diagnosed PC, collected from the database of two skin cancer clinics in Italy (Firenze, Pistoia) from 2000 to 2020, was conducted.

RESULTS

Among the 52 patients with 53 tumors, 31 were men (59.6%) and 21 were women (40.4%) with an age range of 49-96 years (median age 82 years). The most common locations were the head/neck region in men (34% in men vs. 17% in women) and the lower limb in women (17% in women vs. 9% in men). Forty-eight cases (91%) underwent local excision. Of these patients, two (4%) experienced local recurrence, and one (2%) developed a second PC on a different anatomical site 1 month after the primary tumor's excision. Lymph node metastases were present in three cases (6%). Two of them have been treated surgically with adjuvant radiotherapy (both are disease-free after a 2-year follow-up period), whereas the third case developed visceral metastases followed by PC-related death.

CONCLUSIONS

This study, with 52 patients with 53 tumors covering a follow-up period of more than 5 years, shows a less aggressive behavior of PC with 4% local recurrence, 6% nodal metastases, and 2% mortality.

Treatment of Malignant Adnexal Tumors of the Skin: A 12-Year Perspective

Malignant adnexal cancers of the skin—extremely rare neoplasms—are mostly reported as non-symptomatic, slow-growing nodules. These carcinomas occur mainly in the middle-aged (50–60 years of age); they are mostly localized on the upper part of the body and are locally aggressive, infiltrate surrounding tissue, and metastasize to regional lymph nodes. The patients’ outcomes depend on multiple prognostic factors, including the size of the primary tumor and its mitotic count. Surgical resection of the primary tumor with or without regional lymph nodes is the treatment method of choice; however, due to aggressive tumor behavior, perioperative treatment may be considered. The role and efficacy of radiotherapy in the treatment of skin adnexal malignancies are not yet fully defined. Some authors suggest that adjuvant radiotherapy may be considered in locally advanced and regional disease. The aim of this study was to evaluate treatment outcomes and assess the efficacy of combined therapy in patients with adnexal malignancies. Our analysis covered all cases of cutaneous adnexal tumor patients diagnosed and provided with multidisciplinary treatment with surgery and radiotherapy since the beginning of 2009.

Porocarcinoma - a review

From the first report in 1969 to the present day, diagnosis of eccrine porocarcinoma, also known simply as porocarcinoma (PC), remains a challenge. This review presents a concise update of the history, pathogenesis, epidemiology, diagnosis, management and prognosis of this rare sweat gland neoplasm. It differentiates towards the intraepidermal spiral ducts in the eccrine gland, is more common in those over 60 years and often affects the head, neck and lower extremities. PC presents as a dome shaped papule, plaque or nodule growing over weeks to months. The exact incidence is unknown but appears to be rising. Diagnosis is difficult because of variable presentations and similar clinical and histological features to cutaneous squamous cell carcinoma. Management involves removal of the tumour, usually using wide local excision or Mohs micrographic surgery. Prognosis is poor with PC recurring after surgery in 35%. Given the lack of standardised protocols and risk profiles, further studies would help better the understanding of PC.

TROP2 Expression in Sebaceous and Sweat Gland Carcinoma

Sebaceous carcinoma and sweat gland carcinoma (malignant tumors with apocrine and eccrine differentiation) are rare malignant skin adnexal tumors that differentiate toward sebaceous gland and eccrine and apocrine glands, respectively. Owing to the rarity of these carcinomas, standard treatments for advanced disease have not been established. Because the prognosis of patients with systemic metastasis is poor, a new treatment for these diseases is eagerly desired. Trophoblast cell surface antigen 2 (TROP2) and sacituzumab govitecan, an antibody–drug conjugate of TROP2, have attracted attention in the treatment of various solid tumors. In the current study, we immunohistochemically investigated TROP2 expression in 14 sebaceous carcinoma and 18 sweat gland carcinoma samples and found strong and relatively homogeneous TROP2 staining in both cancer types. The mean Histoscore, a semi-quantitative scoring ranging from 0 (negative) to 300, was 265.5 in sebaceous carcinoma and 260.0 in sweat gland carcinoma. These observations directly suggest that both sebaceous carcinoma and sweat gland carcinoma could be potentially treated with TROP2-targeted antibody–drug conjugates such as sacituzumab govitecan.

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Apocrine and Eccrine Differentiation

Adnexal tumors of the skin are a rare group of benign and malignant neoplasms that exhibit morphological differentiation toward one or more of the adnexal epithelium types present in normal skin. Tumors deriving from apocrine or eccrine glands are highly heterogeneous and represent various histological entities. Macroscopic and dermatoscopic features of these tumors are unspecific; therefore, a specialized pathological examination is required to correctly diagnose patients. Limited treatment guidelines of adnexal tumor cases are available; thus, therapy is still challenging. Patients should be referred to high-volume skin cancer centers to receive an appropriate multidisciplinary treatment, affecting their outcome. The purpose of this review is to summarize currently available data on pathogenesis, diagnosis, and treatment approach for apocrine and eccrine tumors.

Eccrine Porocarcinoma: Avoiding Diagnostic Delay

Skin cancer is the most common cancer within the United States. Reports estimate that 1 in 5 Americans will develop some form of skin cancer. Eccrine porocarcinoma is a rare type of skin cancer of sweat gland origin. Eccrine porocarcinoma is most commonly found on the lower extremities. Clinically it may appear similar to benign skin lesions and it has significant metastatic potential. The authors present a case report with 22 months' follow-up. It describes a multiyear delay in diagnosis involving 3 specialties, including primary care, dermatology, and wound physical therapy. Information is given on techniques when high-risk cutaneous cancers are suspected or encountered. A multispecialty treatment plan is discussed.Levels of Evidence: Level V.

A case of YAP1 and NUTM1 rearranged porocarcinoma with corresponding immunohistochemical expression: Review of recent advances in poroma and porocarcinoma pathogenesis with potential diagnostic utility

Porocarcinoma is a rare malignant adnexal tumor with predilection for the lower extremities and the head and neck region of older adults. This entity may arise de novo or in association with a benign poroma. Porocarcinoma's non-specific clinical appearance, immunohistochemical profile, and divergent differentiation may occasionally be diagnostically challenging. Recently, highly recurrent YAP1 and NUTM1 gene rearrangements have been described in cases of poroma and porocarcinoma. In this report, we present a case of porocarcinoma with squamous differentiation in an 81-year-old woman which harbored rearrangement of the YAP1 and NUTM1 loci and was diffusely immunoreactive for NUTM1. We discuss the recent advancements in the pathogenesis of poromas and porocarcinomas with emphasis on the clinical utility of the NUTM1 antibody.